The handling of cementing and production tubing at a wellhead has been done with the aid of an elevator. Prior elevators have handled single, dual and multiple strings. The C. C. Brown U.S. Pat. No. 3,154,145, the E. C. Chamblee U.S. Pat. No. 3,330,354 and the A. J. Penick U.S. Pat. No. 2,298,507 disclose examples of such prior elevators.
Elevators are used for supporting pipe strings in a well, when the string is being made up or broken out, lowering the string into the well and withdrawing the string from the well. Prior devices have used a body with one or more tapered bowls, a set of gripping slips for each bowl, an actuator to raise and lower the gripping slips with respect to their bowl and a means connecting to the body for supporting the elevator.
Disadvantages of the prior art structures which have been encountered are the tendency to bend tube strings when only one string is supported in a dual bowl elevator, damage encountered to the actuators as a result of being hit by the strings or tongs, and the failure of the actuators when lifting the gripping slips from the bowl to cause the main slip segment to be moved outward of the bowl.